Settlement offer not acceptable.

Miway had their own images based assessment of R31K and sent an offer of R6K to me. I took the car in at the same panel beater they went to and assessment amounted to R58K. How is this possible, firstly, they denied liability based on their client altered truth of the accident. When I presented images of the accident scene which proved otherwise and requested them to explain how possible it is for a car parked behind mine to jump out of parking with a switched off engine and damage my car on the left side panel, rear door to front and axle disalignment. They suddenly came up with an offer of 20% based on their image estimate of R31K. I'm deeply disturbed and feel violated because now I have to fix my own car with my own expense cause they clearly don't care what happened and will not take liability of their client's car having crashed into mine. Just because I am a third party doesn't mean that I should be taken advantage of.